Reef One Biorb Silk Plants, Weighted ball keep the plant down, will not float, Size: Large The plants in the biOrb Silk Collection have the vivid colours. And detailed structure of real plants, bringing the beauty of the world's underwater world. To alluring life in your biOrb aquarium. For the biOrb aquariums. Weighted ball keep the plant down, will not float. Vivid colours and detailed structure of real plants.